1. Field of the Invention
This invention relates to apparatus for driving casing, piles, or conductor pipe and more particularly to an apparatus comprising in combination; an external reciprical impact driving means supported atop the conductor pipe, internal rotatable drilling means supported within the conductor pipe, and means associated therewith for introducing air and water under pressure for creating a pressure differential to evacuate the drilling debris and cuttings to the surface. The drilling means is supported within said conductor pipe at the bottom portion thereof near the point of least energy absorbtion and rebound. The driving and drilling operations may be performed simultaneously or sequentially.
2. Brief Description of the Prior Art
Apparatus for driving casing or conductor pipe are known in the art, there are several patents which disclose various devices for accomplishing this end most of which merely provide for drilling in advance of the lower end of the casing.
Wiredal, U.S. Pat. No. 4,408,669 discloses a drilling means having a pilot bit, a reamer, and a guide member mounted in the bottom end of a casing tube, and which transmits impacts to the casing. The guide member has a plurality of channels which are segments of a spiral through which drilling debris is discharged upwardly to the casing tube.
Tschirky, U.S. Pat. No. 4,133,396 discloses a fluid motor and drill apparatus supported in the casing, with the drill extending below the lower end of the casing to drill the bore hole in advance of the casing.
Pulk, et al, U.S. Pat. No. 3,870,114 discloses a ground drilling apparatus which is operated from within a casing which is sunk into the hole drilled by the drill unit. The casing is pulled without rotation into the hole by a drill bit which includes a pilot bit having an axis which coincides with the centerline of the drill hole and is parallel to and separate from the cendral axis of the drill unit which is the line of action of the percussion force.
Sewell, U.S. Pat. No. 2,330,083 discloses a wireline retractable drill bit which is locked into drilling position within a casing by outwardly extendable dog members.
Kammerer, U.S. Pats. Nos. 3,097,706 and 3,097,707 discloses an apparatus for drilling well bores with casing. The apparatus is lowered through a bore of a string of drill pipe that will form the ultimate casing for the well bore, positively coupled to the lower portion thereof, and rotating the casing the accomplish the drilling of the bore.
Kammerer, U.S. Pat. No. 3,196,960 discloses a fluid expansible rotary drill bit in which greater fluid pressure can be developed in the bit for expanding its cutters outwardly, and in which the bit permits a large flow of circulating fluid through it for cleaning the bit and flushing the cuttings from the well bore.
The following patents of interest issued to Brown disclose apparatus for drilling wells using the casing itself as the drill string: U.S. Pats. Nos. 3,552,507; 3,552,507; 3,552,508; 3,552,509; 3,552,510; 3,656,564; and 3,747,675 disclose apparatus employing well casing as the drill string, a drill bit having radially expansible cutters insertable and removable through the bore of the casing and releasably connected thereto, and a drive connection means releasably insertable into the upper end of the casing bore including gripping means engageable with the casing bore for transmitting rotational torque to the casing.
The prior art in general, and none of these patents in particular, disclose the present apparatus for driving casing, piles, or conductor pipe into the ground which comprises in combination, an external reciprical impact driving means supported atop the conductor pipe, internal rotatable drilling means supported within the conductor pipe, and means associated therewith for introducing air and water under pressure for creating a pressure differential to evacuate the drilling debris and cuttings to the surface. The drilling means being supported within said conductor pipe at the bottom portion thereof near the point of least energy absorbtion and rebound.